Do not prompt to join mailing list when running under Docker
Do not prompt to join mailing list when running under Docker

This is because SequenceServer creates a file in DOTDIR to remember
that it has asked the user once. However, this file doesn't persist
when running under Docker and SequenceServer tends to prompt users
repeatedly. Furthermore, a prompt can be annoying for automated
setups which is likely the primary use case of Docker build.

see #468

Signed-off-by: Anurag Priyam <6e6ab5ea9cb59fe7c35d2a1fc74443577eb60635@gmail.com>

yeban/sequenceserver,yeban/sequenceserver,yeban/sequenceserver,yeban/sequenceserver